Perfluorocyclohexene bridges in inverse DiArylEthenes: synthesis through Pd-catalysed C–H bond activation, experimental and theoretical studies on their photoreactivity

A curve-crossing model to rationalize and optimize diarylethene dyads

“…Monomers of DAE using the latter cyclohexene bridge have been synthesized, but were found to be less effective that the corresponding perfluororcyclopentene structures. 48 , 49 On balance, the maleimide group ( r ) is probably the most pertinent “bridge” option to increase the tilt. In DAE monomer, this maleimide bridge yields however less efficient cyclization than the well-known perfluorocyclopentene bridge, especially in polar environments.…”

Light‐Controlled Release and Uptake of Zinc Ions in Solution by a Photochromic Terthiazole‐Based Ligand

“…The fact that zinc metalated 1 a remains photochromic is not unexpected as, unlike its previously reported copper or nickel counterparts, the zinc complex lacks the MLCT band that could potentially deactivate the excited state and quench the photoreaction. Moreover, as revealed by the crystal structure, the two terminal thiazolyl groups of each ligand in the dimer are packed in the photoactive antiparallel conformation with respect to the central thiazolyl, and the distance between the two potentially photo‐reactive carbons within each ligand is approximately 3.71 Å (between C12 and C38) and 3.77 Å (between C28 and C52), which is much shorter than the generally admitted upper limit 4.2 Å to allow the photochemical reaction in the crystalline state or in solution …”

“…The fact that zinc metalated 1a remains photochromic is not unexpected as, unlike its previously reported coppero r nickel counterparts, [27] the zinc complex lacks the MLCT band that couldp otentially deactivate the excited state and quench the photoreaction.M oreover, as revealed by the crystal structure, the two terminal thiazolyl groups of each ligand in the dimer are packed in the photoactive antiparallel conformation with respect to the central thiazolyl, and the distance between the two potentially photo-reactive carbonsw ithin each ligand is approximately 3.71 (between C12and C38) and 3.77 (between C28 and C52), which is much shorter than the generally admitted upper limit 4.2 to allow the photochemical reaction in the crystalline state or in solution. [28,29] Based on the spectral features of 1a and 1b ( Figure S1 in the Supporting Information), the photochromic behavior of Zn 2 -(1a-2 H) 2 and its spectral evolutions in the dark can be tentativelyi nterpreted as follows. Irradiation at 405 nm would first lead to az inc complexw ith one or (and) two 1b,Z n 2 -(1a-2H)(1b-2 H) or (and) Zn 2 -(1b-2 H) 2 ,c haracterized by as pecific absorption band at 462 nm.…”

Palladium-Mediated Organofluorine Chemistry

“…Coupling of fluorinated aryl halides with enolate precursors, 115,116 polyfluorovinyl chlorides with thiophenes, 117 and perfluorophenyl carboxylic acids with arenes have been reported. 118 However, in this section, more attention will be paid to those reactions where C-H activation occurs on the fluorinated coupling partner.…”